Dental laboratory instrument.



Patented Feb. 1, 1919.

| Emil J. S. DAVIDSON. DENT-AL LABORATORY INSTRUMENT.

APPLICATXDN FILED APR. :8, m1. RENEWEDYDEC. 6,1918.

vs &I

JAMES S. DAVIDSON, 0F WHEELING,

WEST VIRGINIA.

DENTAL LABORATORY INSTRUMENT.

Specification of Letters Patent.

Patented Feb. 4, 1919.

' Application filed April 18, 1917; Serial No. 163,055. Renewed December 6, 1918. Serial No. 265,671.

To all whom it may concern:

Be it known that I, JAMES S. DAvnosoN, a citizen of the United States, and a resident of Wheeling, inthe county of Ohio and State of West Virginia, have invented a certain new and useful Improvement in Dental Laboratory Instruments, of which the following is a specification.

The present invention relates to an improved instrument adapted for use in dental laboratories and the like, and has for an object to provide an instrument of this character embodying the features usually required in four or more separate instruments.

The present invention is designed to offset the delay in locating misplaced instruments, and delay in picking up and laying down a number of different instruments which are required to be used successively in carrying out a certain process of work.

For instance, at the present time four separate instruments are usually employed in setting upand finishing an artificial plate of teeth. The present invention designs to provide a single instrument embodying parts which take the place of these four separate instruments and which may always be grouped together so that no lossof time or material will result from the temporary misplacement of an instrument.

The invention further aims at the provision of a handle open at one edge and pro vided with a plurality of blades ormembers pivotally mounted in the handle and being so arranged therein as to interfit and mesh snugly together in the handle and in a relatively small space. V

The above, and various other objects and advantages of this invention will be in part described, and in part understood, from the following detailed description of the present preferred embodiment, the same being illustrated in the accompanying drawing wherein Figure 1 is an edge view of the instrument constructed according to the present invention, disclosing the blades or parts thereof in closed position.

Fig. 2 is a side elevation of the same.

Fig. 3 is a longitudinal section taken submodels, and the like.

stantially vertically and centrally through the instrument with the blades or parts thereof closed.

Fig. 4 is a similar view taken longitudinally through the adjacent side of the in strument as shown in Fig. 2.

Fig. 5 is a transverse enlarged section taken substantially on the line 5-5 of Fig. 1.

Fig. 6 is a transverse section taken substantially on the line 6-6 of Fig. 1.

Referring to this drawing, 10 and 11 designate a pair of side plates which are arranged in spaced-apart relation by the provision of a pair of longitudinally extending spacers 12 and 13 in the form of springs of the leaf type. A partition strip 15 extends longitudinally of the side plates 10 and 11, is arranged between the same, and has one edge interposed between the springs 12 and 13. These springs 12 and 13 are relatively fiat, are arranged between the side plates 10 and 11, at one edge of the handle to provide a pocket or recess extending throughout substantially the entire length of thesame, and are pivotally connected to the side plates 10 and 11, by means ofa transverse pin 14 which is carried by the side plates intermediate the ends thereof.-

The springs 12 and 13 are free at their 0pposite ends and are adapted to receive thereagainst the annularly faced shanks or butt ends 16 of elements which are pivotally mounted upon pins 17 and 18 extending transversely across the side plates 10 and 11 adjacent to the opposite ends thereof for uniting the plates and providing a relatively rigid handle structure.

In one end of the handle, preferably mounted upon the transverse pin 17, and at one side of the blade 19 which is the same width exception of the point which is abruptly rounded off as shown. This knife'or blade is adapted for preferably of substantially knife 19 engages against the adjacent spring 12 to yieldingly hold the knife 19 in either open or closed position. The pin 17 of the handle also pivotally supports a chisel 20 partition 15, is a knife from end to end with the use in trimming plaster The shank 16 of the or the like which is arranged in the handle at the opposite side of the partition 15, and which is adapted to engage at its shank portion 16 against the adjacent free end of the spring 13. The chisel 20 is adapted for use to trim the rubber from around the teeth after the plate has been vulcanized. In the opposite end of the handle, pivotally mounted upon the pin 18, is a spatula 21 and a scraper 22. These instruments 21 and 22 are provided with the shanks 16 which are pivoted upon the pin 18 and arranged at opposite sides of the partition wall 15, the shanks extending forwardly in the 0pposite sides of the handle for a considerable distance, and the outer ends of the instruments, which by their peculiar formation, are offset laterally from the shank or handle thereof, are passed over the free edge of the partition wall 15 into one side of the handle, adjacent to the plate 11. The instruments 21 and 22 may be of a length such as to over lap the instrument 19 in the other end of the handle when all of the instruments are closed within the handle.

From Figs. 2 and 3, it will be noted that the partition wall 15 is reduced in height and provided with a shoulder 23 over which passes, and against which is secured the shank portion of the instrument 21. The instrument 21 is thus supported by the shoulder 23 and the upper edge of the wall 15, the shoulder 23 holding the instrument 2lsfrom swinging laterally across the partition wall. The scraper 22 is flattened and dished at its free end to receive snugly thereagainst the extremity of the spatula for accommodating both of the instruments 21 and 22 in the same end of the handle. The free end of the scraper 22 is ofi'set laterally, and the adjacent side 11 is preferably recessed to form a pocket 24: which opens through the free edge of the side 11, and which is adapted to receive therein the said scraper 22 when the latter is sprung into a closed position.

It is of course understood that the instruments or members 19, 20, 21 and 22 may be opened and closed in the manner of the blades of a penknife, and that each member or blade 'of the instrument comprises in itself a separate instrument. Thus, the four or more separate instruments which may be mounted and peculiarly nested in the handle, are collected together and cannot be misplaced, and are each so arranged in the handle that access may be readily had thereto, one at a time, for bringing the same into operation'as the step in the method of the Work proceeds. The inner edges of the instruments 21 and 22 are protected from contact with-the closure springs 12 and 13, and thus protect it from injury, not only by the action of the springs 12 and 13 against the shank 16 thereof, but also by virtue of the lateral offsetting of the spatula and the forming of the shoulder 23 in the partition wall to receive the same. The various instruments or members employed may. be provided at any suitable point throughout their length with thumb notches 25 arranged opposite to recesses 26 formed in the usual manner in the opposite side plates 10 and 11.

It is necessary to provide the blade 19 of considerable length, and for accommodating the same in the handle, the instruments 21 and 22 are ofiset laterally toward the op .posite side of the handle so that the instruments 21 and 22, and the handle 19, overlap.

It is of course understood that various changes and modifications may be made in the details of construction of the above specifically described embodiment of the invention without departing from the spirit thereof, and being restricted only by the scope of the fol-lowing claims.

I claim 1. In a device as specified, the combination of a hollow handle open at its front edge andprovided with a spring back and a central longitudinally extending partition, an instrument pivotally mounted in each end of the handle at each side of the partition, one of the instruments having an enlarged free end laterally ofl'set to overlap the free end of the opposed instrument at the same side of the partition when closed, said partition being recessed :to provide a supporting shoulder over which the offset portion of said first instrument is adapted to engage for supporting the enlarged end of the instrument.

2. In a device as specified, the combination of a hollow handle having a central partition, a shank pivoted in the handle at 105 each side of the partition, :said shanks having spoon-shaped free ends oflfset in the same direction toward one side of the handle, and the-handle having a recess in its inner wall to receive theend of the adjacent 110 shank, the partition being recessed to receive the other shank thereacross, and the spoon-shaped free ends of the shanks lying closely adjacent each other and the said side of the partition.

3. In a device as specified, the combination of a hollow handle, a pair of shanks pivotally mounted in one end of the handle and adapted to swing into the latter, a second pair of shanks pivotally mounted in the 120 opposite end of the handle, an intermediate partition extending longitudinally in the handle between the shanks of each pair, one of said shanks being provided with a bowlshaped portion ofi'set laterally from the 125 shank toward the opposite side of the handle, and said partition being cut away to receive the offset portion of the shank when the latter is closed, the adjacent shank of the pair being flattened and curved to sub- 130 stantially the configuration of the convexed the longitudinal plane of said first shank, surface of the bowl to snugly engage against and the opposite shank of the opposite pair the latter, and the adjacent side of said being relatively short and arranged in the 10 handle being recessed to provide a pocket plane of said curved portions of the second 5 for the reception of said flattened portion pair of shanks.

of the second shank, one shank of the opposite pair being elongated and arranged in JAMES S. DAVIDSON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Eatents, Washington, D. G. 

